The present invention relates to microreactor technology. Microreactors are commonly referred to as microstructured reactors, microchannel reactors, or microfluidic devices. Regardless of the particular nomenclature utilized, the microreactor is a device in which a sample can be confined and subject to processing. The sample can be moving or static, although it is typically a moving sample. In some cases, the processing involves the analysis of chemical reactions. In others, the processing is executed as part of a manufacturing process utilizing two distinct reactants. In still others, a moving or static target sample is confined in a microreactor as heat is exchanged between the sample and an associated heat exchange fluid. In any case, the dimensions of the confined spaces are on the order of about 1 mm. Microchannels are the most typical form of such confinement and the microreactor is usually a continuous flow reactor, as opposed to a batch reactor. The reduced internal dimensions of the microchannels provide considerable improvement in mass and heat transfer rates. In addition, microreactors offer many advantages over conventional scale reactors, including vast improvements in energy efficiency, reaction speed, reaction yield, safety, reliability, scalability, etc.
Microreactors are often used in chemical processes where the reactants comprise liquids and gases and the microreactor is designed to mix gas and liquid reactant phases to produce one or more specific product molecules. In order to perform a high yield or high selectivity gas/liquid reaction, it is often necessary to provide a relatively high interfacial surface area between the gas and liquid phases of the reaction. Although, the gas and liquid phases may exhibit a variety of degrees of miscibility, in many cases the reactants are immiscible under ordinary conditions. Accordingly, the present inventors have recognized the need for microreactor schemes that can improve yield and selectivity, even for relatively immiscible gas and liquid reactants, particularly for microreaction technology at production level.
According to one embodiment of the present invention, a microreactor assembly is provided comprising a fluidic microstructure and an injector assembly. The injector assembly comprises a liquid inlet, a gas inlet, a liquid outlet, a gas outlet, a liquid flow portion extending from the liquid inlet to the liquid outlet, and a gas flow portion extending from the gas inlet to the gas outlet. Further, the injector assembly defines a sealed injection interface with a microchannel input port of the fluidic microstructure. The injector assembly is configured such that the gas outlet of the gas flow portion is positioned to inject gas into the liquid flow portion upstream of the liquid outlet, into the liquid flow portion at the liquid outlet, or into an extension of the liquid flow portion downstream of the liquid outlet. Further, the injector assembly is configured such that gas is injected into the liquid flow portion or the extension thereof as a series of gas bubbles. The resulting microreactor assembly, and the injector assemblies utilized therein, which can be used with a variety of microreactor designs, effectively improves the interfacial surface area within the microstructure without requiring excessive reduction of microchannel dimensions.